The present invention relates generally to intrinsically safe valves and, more particularly, to valves that employ a piezo-electric element that operates using minimal electrical energy.
Many industries utilize and/or manufacture flammable chemicals. These industries must take particular caution to prevent ignition of such chemicals in order to prevent fires or explosions. Chemical management systems require significant consideration towards minimizing the potential for igniting such chemicals. Chemical management systems typically are designed so that arcing and sparks which often result from connecting and disconnecting electrical circuits is minimized. Presently, such chemical management systems utilize expensive wiring and switch elements in order to achieve this goal.
One particular example of such a chemical management system utilizes solenoid valves in order to displace a valve element to control the flow of flammable chemicals. Present systems utilize expensive low spark implementations. These implementations include sparkless wiring and sparkless switches which are expensive because of the significant shielding of the wiring and sealing of the switches. Even though these switches typically operate at a signal voltage level rather than a higher, working voltage levels, minimal sparks in a highly flammable environment can present extremely hazardous situations.
Thus, there is a need for providing an intrinsically safe valve which reduces the overall cost of valves in a chemical management system.
In accordance with the teachings of the present invention, a valve system is disclosed that employs a low voltage element, such as a piezo-electric element, to activate a fluid flow valve so as to use a minimal amount of electrical energy. In one embodiment, the piezo-electric element activates a pilot pressure valve, which allows a control fluid to pass to a main control valve. The control fluid causes the main control valve to activate a working element, which is turn operates the fluid flow valve. A switching assembly is employed to activate the piezo-electric element. The switching assembly can include various types of switching devices, such as RF switching devices, optical switching devices, infrared switching devices and low voltage electrical switching devices, to allow the valve to be controlled from a remote location.
For a more complete understanding of the invention, its objects and advantages, reference should be made to the following specification and to the accompanying drawings.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.